Constant-mesh variable-speed gear



. March 10, 1931.

CONSTANT MESH VARIABLE SPEED GEAR Filed Oct. 8, 1929 2 Sheets-Sheet l 520 145 c f I V: m 1 9 a K 1 6 J.- WARD I 1,795,981

March 10, 1931. WARD CONSTANT MESH VARIABLE SPEED GEAR Filed Oct. 8, i2 2 Sheets-Sheet 2 Patented Mar. 10, 1931 PATENT; OFFICE JOHN WARD, OF BLACKBURN, ENGLAND CONSTANT -MESH VARIABLE-SPEED GEAR Application filed October 8, 1929, Serial No. 398,230, and in Great Britain October 16, 1928.

This invention refers to a constant-mesh, variable speed gear, chiefly as used with motor-propelled vehicles.

The object of the invention is to provide a constant-mesh variable speed gear of improved and simplified construction, and one in which few parts are required to be moved to efiect a change of speed, forward or reverse.

According to the invention, the improved variable speed gear comprises a spur wheel, an internally toothed drum, a pair of constant-mesh pinions carried by an intermediate disc, brake mechanism for said disc and means for engaging either one or both of the pinions with the internally toothed drum to provide alternatively a geared forward, and a locked gear train with or without a reverse gear. Various methods of obtaining intermediate forward speeds may be adopted, and one method comprises a third pinion in constant driving connection with one of the pinions of the said pair of pinions and gearing with a second internally toothed gear drum with brake mechanism, to provide a second or intermediate forward speed. Means may also be provided for facilitating synchronizing of the gearing for changing to the locked or direct drive.

Where more than two forward intermediate speeds are desired, the improved gear may also comprise one or more additional engine-driven spur wheels, and one or more additional internally toothed gear drums and axle of each additional pinion being carried by the preceding drum. Y

Upon the accompanying drawing Fig. 1 is a sectional elevation of one ex ample of gear made in accordance with the invention.

Fig. 2 is an end elevation of Fig. 1 with the cover removed.

As illustrated, the improved gear comprises a spur wheel a keyed to the driving shaft 6. Integral with the driven shaft 0 is an internally toothed gear drum (2!. Alongside such drum d is a sliding intermediate disc 6, and by such intermediate disc are carried the axles of two constantly meshing pin additional pinions to engage said drums, the

ions 7 and g, of equal diameter. The axle of the pinion f is carried through the disc and a further and equal broad width pinion 7 provided thereon meshing with the spur wheel a. The pinion f has two toothed portions f and f of equal width to the toothed portion (Z of the drum (Z and separated by a space f wider than such toothed portions. The pinion g has one wide toothed portion 9 part of which is constantly in mesh with the portion f and the other part of which registers with the space 7. Such latter part of the toothed portion g and the toothed portion f are adapted to selectively engage with the toothed portion (Z by sliding the disc. The sliding disc e is provided with brake mechanism h whereby it may be held stationary, or made free at will. A further internally toothed drum y is provided, rotatably mounted on the shaft 6, meshing with the pinion f and provided with brake mechanism j On such drum is a pinion 3' which meshes with a third toothed drum is having brake mechanism 70 and also meshing with an additional spur wheel m keyed to the shaft 2). The gear is enclosed within a' casing '12, in which is slidably mounted a selector rod 0, having an arm p adapted to engage a flange 9 on the sliding disc 6 so as to slide the same, and tappets s are adapted to engage and operate rockers 2, for the respective brake mechanisms when a rocking motion is given to the selector rod.

The operation of the gear is as follows For reverse, the sliding disc 6 is positioned as shown in Fig. 1, and thebrake mechanism for the disc is brought into action to check rotation of the disc. For 1st forward speed, the sliding disc is moved to bring the toothed portion g of the pinion 9 into mesh with the toothed portion d of the drum (Z at the same time taking the toothed portion f of the pinion f out of engagement with the toothed portion (Z of the drum cl. The drive is obtained progressively as the brake mechanism for the disc 6 is applied to check its rotation.

For 2nd and 3rd forward speed, the sliding disc is moved another step but the relative meshing of the pinions is unchanged the purpose of the movement being to enable with vice such'las has previously been. provided.

to bring the toothed portion f into engage ment withthe toothed portion (Z1 d when the gears will be locked.

The brake mechanism is shown diagramof the drum matically as consistingof' brake hands and,

drums, but any suitable clutch orbrake mech-v anism may be used. The arm p would preferably be formed as a double-armed grooved lever extending-to opposite sidesiof the disc e, and of such design as will maintain contact between p and .9 when theselector rod. 0 is rocked. a w

The precisemanner of slidably' operating the pinions may vary. The pinion-carrying disc and the pinions carried bylsuch disc preferably slide aseone, said. pinio'ns'being of such width laterally (one ofthem being also circumferentially grooved) and so mounted as tions. a

' The putting on of more than one brake at to effectthe desired gear variaone time will provide a braking system for the driving and driven shafting, that is, for

the whole of the drive. I In order to facilitate the interlocking ofthe pinionfwithlthe drum cl for top gear drive and prevent any possibility of gear clashing when such interlocking takes place, the wheel j(in the case of a 3-speed box) or, the wheel In, (in the'case of a li-speedbox) maybe made free, to slide laterally, and may be provided upon a companion-clutch facing fixedeither directly upon the shaft 6 or upon the side 1 surfaces of the spur wheel a, or m respec tively. I,

As shown .in Fig 1, the drum 7c is 'made i with an extension 79 having aconical clutch face Jr' and enlarged around the shaft to house a spring and thrust race 70 On the shaft isprovided a clutch {member Z2 a The ear is applic ble formany uses, as for exampf e, on a imotor-eycleand where :as in this case, a reverse g earis not required the toothed omitted.

v The improved gear provides a dire t drive? which a is positive and needs no clutching do ;-Whja.tl claim is:-f.

Wheel and an internally toothed pinions carried .onian: intermediate member provided with brake mechanism and SElQCtlV-E a miniature clutch facing to actuate set forth. l

4. In, an epicyclic variable speed gear :having a sun wheel and an internally toothed j: drum keyed to shafts and together forming, themain members o the geanand planetary pinions carried on an intermediate m m erportion, ff of pinion may he the said main members, a pair ofplarietary:

pinions having toothed portions *part of whichare in constant mesh with each other and each having another part of thetoothed portion not in mesh, the said planetary pm ions being slidable-together relatively to one f -the. said mainm erssotha Qneof 1 said other parts oftheirtoothed portions ,or a

the meshing parts of the said planetarypim ions may be engaged with such mainmember.

.togive forward, reverse or locked drive :re-: a

spectively.

2. In an epicyclicvariable speed gear hav 7 ing a sun wheel and an internally toothed drum keyed to '"shaftsand together forming the main members of the gear, and planetary pinions carried on an intermediate'memberprovided with brake mechanism,vand selec-i; tively and slidably meshing with and {connecting the said main members, a pair lof planetary pinions, having toothed portions part of which are in constant'mesh with each a, 1' i 7 other. and each having another part of the toothed portion not in mesh, the said plane; a V 1 ea tary pinions bein g slidable together relatively to one of the said main members, so that one of the said other parts of their toothed porvtions or the meshing parts of'the said plane tary pinions may be engagedwithsuch main member to give forward, reverse or locked drive. respectively, in combination a, second a inter ally toothed dr m connected by plane tary pinions to the sun wheel aforesaid and brake mechanism for said second" toothed drum, whereby further ,gear ratios, may be p ovided,

',3' .V An epicyclie gear according claim M 2.,'lfhar terized .int a the e nd toothed d um me he wi h one of the slidablep a tary ,pinions'in mesh With the sun wheel, asv

pirovide with 'brake mechanism, andselec i iYely and slidah v meshing with, and icon meeti g ,the said m in members, allpair' of.

ive y o one of the said main m mbers; sothat oneof 'sa'id other parts of'their toothed Iporf-T a tions or the meshing parts of the said planetary pinions maybe engaged I Y In al epicyclioWariablespeed'gear hava ing a sun drum keyed to shafts and. together forming themainmembersofthe gear, and planetary member to give forward, reverse or locked dr ve respect vely, in combination, a second internally tOothed'drum-connectedby planefi I if mechanismfor said seco d a third internally toothed ,drum, a second wheel keyed to the same shaft as the first sun wheel planetary wheels carried on the second toothed drum and meshing with the said second sun wheel and third internally toothed drum and brake mechanism for the said third drum, so as to provide further gear ratios, as set forth.

5. An epicyclic gear according to claim 4, characterized in that the second toothed drum meshes with one of the slidable planetary pinions in mesh with the first sun wheel, as set forth.

6. All epicyclic variable speed gear according to claim 1, characterized in that the planetary pinions of the pair in constant mesh are of unequal width one of them having two single width portions relative to the width of teeth on the internally toothed drum, separated by a space of single width and the other having a double width portion, half of which is in mesh with one of the single width portions aforesaid, and the other half overlapping said single width space, as set forth.

7. An epicyclic variable speed gear according to claim 1, characterized in that the intermediate member is slidably mounted on the driving shaft to provide the sliding movement for the planetary pinions, as set forth.

8. An epicyclic variable speed gear according to claim 1, characterized by coacting clutch parts on the driving shaft and on one of the driving toothed gear drums for synchronizing the said parts preparatory to effecting the engagement of the meshing parts of the said planetary pinions for the locked drive, as set forth.

9. An epicyclic variable speed gear according to claim 1, characterized by clutch mechanism between the last internally toothed I drum and the sun wheel shaft for synchronizing the parts preparatory to efiecting the engagement of the meshing parts of the said planetary pinions for the locked drive, as set forth.

In testimony whereof I have signed my name to this specification.

JOHN WARD. 

